Optoelectronic devices are known. For example, integrated silicon waveguide devices, which are mounted on a rigid substrate prior to connecting to an electrical lead frame assembly and encapsulation to form a sealed product. In the case of integrated silicon waveguide devices having a connection to an optical fibre system, it is important to obtain and maintain correct position and orientation of the waveguide device with the optical fibre. It may also be necessary to form electrical connections to the device from a lead frame assembly and to package the assembly in a sealed manner so as to prevent degradation of operation of the optoelectronic device. For this reason integrated silicon waveguide devices may be mounted on a high mechanical modulus substrate such as a ceramic substrate. It has been known to locate such substrates within a premoulded encapsulating casing and to form electrical connections between conductors on the substrate and conductors of a lead frame assembly. Known techniques for interconnection of a ceramic substrate have involved wire bonding from the substrate to the lead frame. This may represent a second wire bonding operation in cases where the optoelectronic device has itself required a first wire bonding operation to connect electrical devices to a conducting network on the substrate. In cases where the substrate is located within the walls of a package, restricted access can present problems in making wire bonded connections inside the walls of the package. Furthermore there may be reduced electrical performance due to the length of wire bonds necessary to connect the substrate to the lead frame.
It is an object of the present invention to provide improved method and apparatus for connecting a supporting substrate to a lead frame particularly when forming an enclosed package.